Falcon Heavy (FH), previously known as the Falcon 9 Heavy, is a spaceflightheavy lift launch vehicle being designed and manufactured by SpaceX. The Falcon Heavy is a variant of the Falcon 9 v1.1 launch vehicle and will consist of a standard Falcon 9 rocket core, with two additional strap-on boosters derived from the Falcon 9 first stage.[7] This will increase the low Earth orbit (LEO) payload to about 53 tonnes, compared to about 13 tonnes for a Falcon 9 v1.1. Due to the Falcon 9 failure investigation, the first launch is now expected in 2016.[8]

At a press conference at the National Press Club in Washington, DC. on 5 April 2011, Elon Musk stated, “Falcon Heavy will carry more payload to orbit or escape velocity than any vehicle in history, apart from the Saturn V moon rocket, which was decommissioned after the Apollo program. This opens a new world of capability for both government and commercial space missions.”[9]

SpaceX originally announced that the Falcon Heavy demonstration rocket would arrive at its west-coast launch location, Vandenberg Air Force Base, California, before the end of 2012,[10] with a launch planned for 2013.[11] After early launches from Vandenberg, the first launch from the Cape Canaveral east coast launch complex was planned for late 2013 or 2014.[9] By late 2012, the company modified the planned first launch date to 2013.[12] Originally, the first launch from the east-coastCape Canaveral launch complex was planned for 2013, but it is currently scheduled for 2015 with the STP-2 US Air Force payload.[13]

While the initial specifications of the new launcher in April 2011 projected LEO payloads of up to 53,000 kilograms (117,000 lb)[14] and GTO payloads up to 12,000 kilograms (26,000 lb),[15] later reports in 2011 projected higher payloads beyond low Earth orbit, including 19,000 kilograms (42,000 lb) to geostationary transfer orbit,[16] 16,000 kilograms (35,000 lb) to translunar trajectory, and 14,000 kilograms (31,000 lb) on a trans-Martian orbit to Mars.[10][17]

By late 2013, SpaceX raised the projected GTO payload for Falcon Heavy to up to 21,200 kilograms (46,700 lb).[18]

The Falcon Heavy falls into the "super heavy-lift" range of launch systems under the classification system used by a NASA human spaceflight review panel.[19] SpaceX states that the Falcon Heavy will be able to deliver more usable payload to orbit than any launch vehicle since the Saturn V (1967–1973);[6]

In April 2015, SpaceX sent the "U.S. Air Force an updated letter of intent April 14 outlining a certification process for its Falcon Heavy rocket to launch national security satellites." The process includes three successful flights of the Falcon Heavy including two consecutive successful flights, and states that Falcon Heavy can be ready to fly national security payloads by 2017. As of April 2015[update], the SpaceX manifest has five Falcon Heavy launches listed, but does not show specific dates.[20]

The Falcon Heavy configuration consists of a standard Falcon 9 with two additional Falcon 9 first stages acting as liquid strap-on boosters,[7] which is conceptually similar to EELVDelta IV Heavy launcher and proposals for the Atlas V HLV and Russian Angara. Falcon Heavy will be more capable than any other operational rocket, with a payload to low earth orbit of 53,000 kilograms (117,000 lb).[11] The rocket was designed to meet or exceed all current requirements of human rating. The structural safety margins are 40% above flight loads, higher than the 25% margins of other rockets.[21]

The Falcon Heavy's designed payload capacity, capabilities, and total thrust are equivalent to the Saturn C-3 launch vehicle concept (1960) for the Earth Orbit Rendezvous approach to an American lunar landing.[22]

The first stage is powered by three Falcon 9 derived cores, each equipped with nine Merlin 1D engines. The Merlin 1D provides a sea level thrust of 620 kN (140,000 lbf) at a specific impulse of 282 seconds,[23] a vacuum thrust of 690 kN (155,000 lbf) at 311 seconds,[23] and is throttleable from 100% to 70%.[24]

The Falcon Heavy has a total sea-level thrust at liftoff of 17,615 kN (3,960,000 lbf), from the 27 Merlin 1D engines, while thrust rises to 20,000 kilonewtons (4,500,000 lbf) as the craft climbs out of the atmosphere.[6] Falcon Heavy has been designed with a unique propellant crossfeed capability, where some of the center core engines are supplied with fuel and oxidizer from the two side cores, up until the side cores are near empty and ready for the first separation event.[25] This allows engines from all three cores to ignite at launch and operate at full thrust until booster depletion, while still leaving the central core with most of its propellant at booster separation.[26]

After the side cores are released, the center engine in each side core will continue to burn for a few seconds in order to control the trajectory of the side booster.[27][28]

All three cores of the Falcon Heavy arrange the engines in a structural form SpaceX calls Octaweb, aimed at streamlining the manufacturing process,[29] and each core will include four extensible landing legs,[28] To control the descent of the boosters and center core through the atmosphere, SpaceX uses small grid fins which deploy from the vehicle after separation.[30] After the side boosters separate, the center engine in each will burn to control the booster’s trajectory safely away from the rocket. The legs will then deploy as the boosters turn back to Earth, landing each softly on the ground. The center core will continue to fire until stage separation, after which its legs will deploy and land it back on Earth as well. The landing legs are made of state-of-the-art carbon fiber with aluminum honeycomb. The four legs stow along the sides of each core during liftoff and later extend outward and down for landing. Both the grid fins and the landing legs on the Falcon Heavy are currently undergoing testing on the Falcon 9 launch vehicle, which are intended to be used for vertical-landing once the post-mission technology development effort is completed.[31]

The upper stage is powered by a single Merlin 1D engine modified for vacuum operation, with an expansion ratio of 117:1 and a nominal burn time of 345 seconds. For added reliability of restart, the engine has dual redundant pyrophoric igniters (TEA-TEB).[7]

The interstage, which connects the upper and lower stage for Falcon 9, is a carbon fiber aluminum core composite structure. Stage separation occurs via reusable separation collets and a pneumatic pusher system. The Falcon 9 tank walls and domes are made from aluminum lithium alloy. SpaceX uses an all-friction stir welded tank. The second stage tank of Falcon 9 is simply a shorter version of the first stage tank and uses most of the same tooling, material and manufacturing techniques. This approach reduces manufacturing costs during vehicle production.[7]

Although not a part of the initial Falcon Heavy design, SpaceX is doing parallel development on a reusable rocket launching system that is intended to be extensible to the Falcon Heavy, first to the booster stage and ultimately to the second stage as well.

Early on, SpaceX had expressed hopes that both rocket stages would eventually be reusable.[32] More recently, in 2011, SpaceX announced a funded development program to build and fly a reusable launch system that will ultimately bring a first stage back to the launch site in minutes — and a second stage back to the launch pad, following orbital realignment with the launch site and atmospheric reentry, in up to 24 hours — with both stages designed to be available for reuse within "single-digit hours" after return.[33]

The reusable launch system technology is under consideration for both the Falcon 9 and the Falcon Heavy. It is particularly well suited to the Falcon Heavy where the two outer cores separate from the rocket much earlier in the flight profile, and are therefore both moving at a slower velocity at the initial separation event.[33]

As of March 2013[update], the publicly announced aspects of the SpaceX reusable rocket technologydevelopment effort include an active test campaign of the low-altitude, low-speed Grasshoppervertical takeoff, vertical landing (VTVL) technology demonstrator rocket,[34][35] and a high-altitude, high-speed Falcon 9 post-mission booster-return test campaign where—beginning in late-2013, with the sixth overall flight of Falcon 9—every Falcon 9 first stage which was instrumented and equipped as a controlled descent test vehicle to accomplish propulsive-return over-water tests.[31]

SpaceX has indicated that the Falcon Heavy payload performance to geosynchronous transfer orbit (GTO) will be reduced by addition of the reusable technology, but would fly at much lower launch price. With full reusability on all three booster cores, GTO payload will be 7,000 kg (15,000 lb). If only the two outside cores fly as reusable cores while the center core is expendable, GTO payload would be approximately 14,000 kg (31,000 lb).[36] "Falcon 9 will do satellites up to roughly 3.5 tonnes, with full reusability of the boost stage, and Falcon Heavy will do satellites up to 7 tonnes with full reusability of the all three boost stages," [Musk] said, referring to the three Falcon 9 booster cores that will comprise the Falcon Heavy's first stage. He also said Falcon Heavy could double its payload performance to GTO "if, for example, we went expendable on the center core."

SpaceX announced a number of changes to the Falcon Heavy rocket in 2015, and intends parallel design changes to the existing Falcon 9 v1.1 launch vehicle as well. The "new Falcon 9" has not yet been named, as of March 2015[update].[37]

The new Falcon Heavy design will utilize as the two side cores the same core as the "new Falcon 9", while the center core of the Falcon Heavy will be a core with the original Falcon 9 v1.1 dimensions and structure. Design changes to the Falcon Heavy side cores will include a new propellant mix, changes to the launch vehicle thrust structure, a higher-performance engine—the Merlin 1D has completed a substantive round of additional qualification testing since it was initially used in late-2013 on the initial Falcon 9 v1.1 missions—and several size and volume changes to the first stage and second stage propellant tanks.[37]

Changes will also be made to the second stage, but as of mid-March 2015, public sources on second stage detailed changes have only been only explicit about changes to the Falcon 9 second stage.[38]

At an appearance in May 2004 before the United States Senate Committee on Commerce, Science, and Transportation, Elon Musk testified, "Long term plans call for development of a heavy lift product and even a super-heavy, if there is customer demand. We expect that each size increase would result in a meaningful decrease in cost per pound to orbit. ... Ultimately, I believe $500 per pound or less is very achievable."[39] This $500 per pound goal stated by Musk in 2011 is 35 percent of the cost of the lowest-cost-per-pound LEO-capable launch system in a circa-2000 study, referenced by spaceref.com in 2001, the Zenit, a medium-lift launch vehicle that can carry 14,000 kilograms (30,000 lb) into LEO.[40]

As of March 2013[update], Falcon Heavy launch prices are below $1,000 per pound ($2,200/kg) to low-Earth orbit when the launch vehicle is transporting its maximum delivered cargo weight.[41] The published prices for Falcon Heavy launches have moved some from year to year, with announced prices for the various versions of Falcon Heavy priced at US$80-125 million in 2011,[14]US$83-128 million in 2012,[15]US$77.1-135 million in 2013,[42] and US$85 million for up to 6,400 kg to GTO (with no published price for heavier GTO or any LEO payload) in 2014.[43] Launch contracts typically reflect launch prices at the time the contract is signed.

SpaceX has claimed the cost of reaching low Earth orbit can be as low as US$1,000/lb if an annual rate of four launches can be sustained, and as of 2011 planned to eventually launch 10 Falcon Heavy and 10 Falcon 9 annually.[10] A third launch site, intended exclusively for SpaceX private use, is planned at a site near Brownsville, Texas. SpaceX expects to start construction on the third Falcon Heavy launch facility, after final site selection, no earlier than 2014, with the first launches from the facility no earlier than 2016.[44] In late 2013, SpaceX had projected Falcon Heavy's inaugural flight to be sometime in 2014,[6] but as of March 2014[update] expects the first launch to be in 2015[45] due to limited manufacturing capacity and the need to deliver on the Falcon 9 launch manifest.[8]

The Falcon Heavy is being developed with privatecapital. No government financing is being provided for its development.[46]

In May 2012, SpaceX announced that Intelsat had signed the first commercial contract for a Falcon Heavy flight. It was not confirmed when the first Intelsat launch would occur, but the agreement will have SpaceX delivering satellites to geosynchronous transfer orbit.[57][58]

Beyond the Red Dragon concept, SpaceX announced in May 2015 that they are positioning Dragon V2 spacecraft variants—in conjunction with the Falcon Heavy launch vehicle—to transport science payloads across much of the solar system, in cislunar and inner solar system regions such as the Moon and Mars as well as to outer solar system destinations such as Jupiter's moon Europa. Details include that SpaceX expects to be able to transport 2,000–4,000 kg (4,400–8,800 lb) to the surface of Mars, including a soft retropropulsive landing using SuperDraco thrusters following a limited atmospheric deceleration. When the destination has no atmosphere, the Dragon variant would dispense with the parachute and heat shield and add additional propellant.[65]

^ abSvitak, Amy (2014-03-10). "SpaceX Says Falcon 9 To Compete For EELV This Year". Aviation Week. Retrieved 2014-03-11. 'We need to find three additional cores that we could produce, send them through testing and then fly without disrupting our launch manifest,' Musk says. 'I'm hopeful we'll have Falcon Heavy cores produced approximately around the end of the year. But just to get through test and qualification, I think it's probably going to be sometime early next year when we launch.'

^HSF Final Report: Seeking a Human Spaceflight Program Worthy of a Great Nation, October 2009, Review of U.S. Human Spaceflight Plans Committee, p. 64-66: "5.2.1 The Need for Heavy Lift ... require a “super heavy-lift” launch vehicle ... range of 25 to 40 mt, setting a notional lower limit on the size of the super heavy-lift launch vehicle if refueling is available ... this strongly favors a minimum heavy-lift capacity of roughly 50 mt ..."

^"SpaceX Unveils Plans To Be World’s Top Rocket Maker". Aviation Week and Space Technology. 2011-08-11. Retrieved 2011-08-07. Revealing several new details of the 1D, Tom Mueller, propulsion engineering vice president, says the engine is designed to produce 155,000 lb. vacuum thrust and have a chamber pressure at “the sweet spot” of roughly 1,410 psia. “We’ve also increased the nozzle expansion ratio to 16 [compared with 14.5 on the Merlin 1C],” says Mueller, who adds that the initial engine “is doing better than we hoped.” The engine is designed for an Isp (specific impulse) of 310 sec. and has a thrust-to-weight ratio of 160:1. “We took structure off the engine to make it lighter. The engine we shipped [for test] to Texas was a development engine and hopefully the production engines will be even better.”

^Nield, George C. (April 2014). Draft Environmental Impact Statement: SpaceX Texas Launch Site (Report) 1. Federal Aviation Administration, Office of Commercial Space Transportation ". pp. 2–3. The center core engines are throttled down after liftoff and up to two engines may be shut down as the vehicle approaches maximum acceleration. After the side boosters drop off, the center core engines throttle back up to full thrust. The center engine in each side core continues to burn for a few seconds after separation to control the descent trajectorie of the side boosters.

^ ab"Landing Legs". SpaceX News. 2013-04-12. Retrieved 2013-08-02. The Falcon Heavy first stage center core and boosters each carry landing legs, which will land each core safely on Earth after takeoff.

^"Octaweb". SpaceX News. 2013-04-12. Retrieved 2013-08-02. The Octaweb structure of the nine Merlin engines improves upon the former 3x3 engine arrangement. The Octaweb is a metal structure that supports eight engines surrounding a center engine at the base of the launch vehicle. This structure simplifies the design and assembly of the engine section, streamlining our manufacturing process.

^ abcLeone, Dan (2014-07-24). "Solar Probe Plus, NASA's ‘Mission to the Fires of Hell,’ Trading Atlas 5 for Bigger Launch Vehicle". Space News. Retrieved 2014-07-25. SpaceX, has three Falcon Heavy launches on its manifest between now and 2017: an inaugural demonstration launch planned for 2015 followed in short order by the shared launch of the National Oceanic and Atmospheric Administration’s Deep Space Climate Observatory and the U.S. Air Force’s Space Test Program-2 experimental spacecraft, and a 2017 launch of a commercial communications satellite for Intelsat of Washington and Luxembourg.

^Wall, Mike (2011-07-31). "'Red Dragon' Mission Mulled as Cheap Search for Mars Life". SPACE.com. Retrieved 2011-07-31. This so-called "Red Dragon" mission, which could be ready to launch by 2018, would carry a cost of about $400 million or less. ... developing the Red Dragon concept as a potential NASA Discovery mission, a category that stresses exploration on the relative cheap. ... NASA will make another call for Discovery proposals in 18 months or so... If Red Dragon is selected in that round, it could launch toward Mars in 2018. ... Assuming that $425 million cap [for NASA Discovery missions] is still in place, Red Dragon could come in significantly under the bar. We'd have money left over to do some science.